Artificial joints, especially knee joints, have already been the subject matter of numerous publications. For instance, German patent specification DE 102 31 538 C1, which is incorporated by reference herein, describes an artificial joint as an endoprosthesis for the human knee joint, comprising a first joint compartment formed by a first condyle and a first socket, as well as a second joint compartment formed by a second condyle and a second socket whereby, opposite from the condyle, a convexity is present laterally on the tibia in the sagittal main functional plane while a concavity is present transversally, and whereby the two contact surfaces of the appertaining joint compartments have an offset in a main functional plane. This translates into a better range of motion for patients in a manner that approximates the natural range of motion.
WO 98/20816, which is incorporated by reference herein, relates to an artificial joint consisting of at least two artificial joint components with curved articulation surfaces, a curved contact line being formed on each of the articulation surfaces.
The artificial joints known from these sources achieve an optimal approximation of the natural range of motion.
However, the replacement of individual contact surfaces of human joints with functional surfaces of artificial joint elements has proven to be problematic in actual practice because the relative position and orientation of the artificial functional surfaces relative to the remaining functional surfaces, or of the artificial functional surfaces among each other, are of decisive significance for the range of motion that can be thus achieved. In actual practice, however, this is not dependent on the skill of the surgeon but rather on coincidence.
Publications likewise known from the state of the art are U.S. patent application no. 2005/0101966, world patent application WO 98/41152 A1, world patent application WO 2004/041097 A1, European patent application EP 14 02 855 B1 as well as U.S. Pat. No. 6,002,859. The entire disclosures of each of the aforesaid publications, are incorporated by reference herein.